Quantifying Urban Growth Pattern Using Remote Sensing And Spatial Metrics: A Case Study In Adama, Ethiopia

Abstract

Urban growth in developing countries is characterized by rapid and unprecedented expansion, necessitating the assessment and quantification of urban growth patterns. This information is crucial for policymakers, resource managers, and urban planners. The city of Adama in Ethiopia faces significant challenges due to rapid urbanization, including land use management, infrastructure development, environmental sustainability, and socio economic equity. However, the lack of comprehensive data-driven analysis and limited modeling efforts hinder effective urban planning and decision-making processes. This research aims to analyze and quantify the spatial and temporal trends and patterns of urban growth in Adama city using satellite remote sensing data and spatial metrics. Landsat multitemporal images from 1991, 2006, and 2022 were utilized, along with land-cover maps produced at different intervals between 1991 and 2022. The satellite images were classified, and land-use/land-cover maps were generated using a maximum likelihood supervised classification method. Five selected spatial metrics were employed to visually and quantitatively evaluate and analyze urban growth. Spatial metrics were computed at class level and landscape-level scales. The findings reveal the initial state of Adama city's land use in 1991, characterized by dominant agriculture, significant forest cover, and limited built-up areas. Between 1991 and 2006, there was a notable increase in built-up areas, indicating significant urban development and potential environmental impacts. From 2006 to 2022, the growth in built-up areas was limited, primarily through the conversion of forested land, emphasizing the significance of agriculture as the dominant land use. The research also quantifies the growth of built-up areas over time, showing a significant increase from 1991 to 2006 and a slower growth rate from 2006 to 2022. Agricultural areas decreased, while forested areas experienced substantial reduction, raising concerns about urbanization impacts and loss of natural habitat. These findings underscore the need for sustainable land management practices and informed urban planning decisions to balance urbanization demands with environmental preservation. Additionally, the research highlights the dynamics of built-up fragmentation and spatial patterns of urban growth, indicating increased fragmentation in 2006 but a reduction by 2022 within specific proximity ranges. The research findings provide a foundation for informed decision-making in urban planning and sustainable land use strategies by enhancing the understanding of urban growth dynamics and spatial patterns.